A conventional hydraulic damper or shock absorber comprises a cylinder which is adapted at one end for attachment to the sprung or unsprung mass of a vehicle. A piston is slidably disposed within the cylinder with the piston separating the interior of the cylinder into two fluid chambers. A piston rod is connected to the piston and extends out of one end of the cylinder where it is adapted for attachment to the other of the sprung or unsprung mass of the vehicle. A first valving system is incorporated within the piston as a safety hydraulic relief valve during the shock absorber's extension stroke of the piston with respect to the cylinder and a second valving system is incorporated within the piston for allowing fluid replenishment above the piston during the shock absorber's compression stroke of the piston with respect to the cylinder.
Various types of adjustment mechanisms have been developed to generate damping forces in relation to the speed and/or amplitude of the displacement of the sprung or unsprung mass. Often, the damping characteristics are a function of an externally mounted control valve. An externally mounted control valve is advantageous in that it may be easily removed for service or replacement. However, often it is difficult or awkward to effectively locate the respective inlet and outlet of the externally mounted control valve onto the outer housing of the shock absorber during assembly on a repeatable basis.